N201RF

HISTORY OF FLIGHTOn November 27, 2022, at 1729 eastern standard time, a Mooney M20J, N201RF, was substantially damaged when it was involved in an accident near Gaithersburg, Maryland. The private pilot and passenger were seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight.

Automatic dependent surveillance - broadcast (ADS-B) data revealed that the airplane departed Montgomery County Airpark (GAI), Gaithersburg, Maryland, on the morning of the accident and flew to Westchester County Airport (HPN), White Plains, New York. The accident occurred on the return flight to GAI while the airplane was operating on an instrument flight rules (IFR) flight plan.

Dark night instrument meteorological conditions prevailed in the area of GAI at the time of the accident. The reported weather at GAI included variable wind at 4 knots, an overcast ceiling at 200 ft agl, and 1.25 statute miles visibility in fog. A convective SIGMET was valid for the accident time.

Federal Aviation Administration (FAA) air traffic control communication information revealed that the pilot was advised to expect the RNAV/GPS A instrument approach procedure at GAI, but the pilot expressed a preference for the RNAV (GPS) RWY 14 approach procedure because the reported weather at GAI was below minimums for the GPS A approach procedure.

The controller cleared the pilot to fly directly to the BEGKA intermediate fix, which was approximately southwest and ahead of the airplane’s position, but instead the pilot turned about 100° to the right. The controller provided heading changes and direct clearances to waypoints on the RNAV (GPS) RWY 14 approach procedure; however, the pilot made a series of left and right turns, near course reversals, or continued established headings as the controller repeatedly requested that the pilot turn to a different heading.

At one point, the controller requested that the pilot confirm he had the BEGKA waypoint and spelled it for him. The pilot responded that he had entered the information incorrectly and was making the correction. About that time, another airplane on approach to GAI announced that visibility was below minima and requested a diversion to another airport. The pilot of that airplane thought a successful completion of the approach by the next airplane was “doubtful.” When asked by the accident pilot, the controller confirmed the airplane ahead of his had performed the missed approach procedure at GAI due to “poor visibility.”

At 1717, 8 miles northeast of BEGKA, the pilot announced the “cloud deck at 2,800 feet and clear above.”

The controller instructed the accident pilot to proceed direct to BEGKA and cleared him for the RNAV (GPS) RWY 14 approach. The minimum altitude at BEGKA, 11.3 nautical miles (nm) from the runway, was 3,000 ft mean sea level (msl). The airplane crossed BEGKA about 2,775 ft GPS altitude as it aligned with the final approach course and continued its descent. The minimum altitude at the final approach fix (TIMBE), 5.2 nm from the runway, was 2,200 ft msl; the airplane crossed TIMBE at 1,500 ft msl. The minimum altitude at JOXOX waypoint, about 2.3 nm from the runway, was 1,280 ft msl; the airplane crossed JOXOX at 750 ft. The final point on the approach procedure, the visual descent point (VDP), was located 1.4 nm from the runway 14 threshold. The airplane crossed the VDP at 587 ft. (See Figure 1.)

Figure 1. RNAV RWY14 GPS approach profile with the airplane’s altitude depicted in blue

About 1.25 miles from the runway and left of the runway centerline, the airplane impacted and became suspended in a power line tower at an elevation about 600 ft msl and 100 ft above ground level. Between JOXOX and the collision with the tower, the airplane descended as low as 475 ft. The published field elevation at GAI was 539 ft msl.

Figure 2 shows flight track information in relation to the runway 14 final approach course, with minimum altitudes for each segment of the approach shown in orange, and the airplane’s altitude at those locations shown in white.

Figure 2. ADS-B flight track information

The airplane was substantially damaged and remained suspended in the tower. During a conversation with 911 call center personnel, the pilot reported, “I got down a little lower than I should have… I thought I was closer to the airport than I was…We could see the ground, but we couldn’t see in front.” After several hours, the occupants safely egressed the airplane with the assistance of rescue and utility personnel. PERSONNEL INFORMATIONThe pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. His FAA third-class medical certificate was issued August 1, 2022, and he declared 1,432 total hours of flight experience on that date.

The pilot completed an instrument proficiency check on February 17, 2022. A review of the pilot’s logbook revealed he did not tally his total instrument flight experience. Entries during the year before the accident suggested 16 hours of actual instrument flight experience and 5.4 hours of simulated instrument flight experience. AIRCRAFT INFORMATIONAccording to FAA and maintenance records, the airplane was manufactured in 1977 and was powered by a Lycoming IO-360-A3B6D, 200-horsepower engine. The airplane’s most recent annual inspection was completed February 1, 2022, at 4,288.5 total aircraft hours. The altimeter static system and altitude reporting equipment were tested in accordance with CFR 91.411 on June 22, 2022.

The airplane was equipped with an IFR-certified Garmin 430 panel-mounted GPS, which allowed the pilot to select the desired airport, procedure, and then select from the approaches displayed in the drop-down menu. The correct sequence of menu selections provided all approach waypoints and precluded the need to manually enter an individual waypoint.

In interviews with local media after the accident, the pilot described the fog at the time of the accident as “pea soup,” and expressed concern about his altimeter working correctly.

Immediately after recovery of the accident airplane, a calibrated altimeter test instrument was installed by an airframe and powerplant mechanic with inspection authority under the supervision of an NTSB investigator. Functionality testing was performed at the as-found setting of 29.40 in the altimeter’s Kollsman window, then 29.92, and finally a Barometric Scale Error Test was performed through a range of 28.10 and 30.99. According to the test report, the altimeter was “well within the test allowable error at all ranges.” METEOROLOGICAL INFORMATIONThe 1656 reported weather at GAI included 1 ¼ statute miles (sm) visibility, an overcast cloud ceiling at 200 ft agl, temperature 11°C, dew point temperature 11°C, and an altimeter setting of 29.45 inches of mercury.

The reported conditions at GAI at 1727 included 2 ½ sm visibility, mist, and an overcast ceiling at 200 ft agl.

Frederick Municipal Airport (FDK), Frederick, Maryland, located about 18 nautical miles northwest of GAI, reported 3 sm visibility and an overcast ceiling at 400 agl about the time of the accident.

A High-Resolution Rapid Refresh (HRRR) atmospheric model sounding for near the accident site identified wet fog between the surface and about 600 ft, low-level wind shear and light to moderate turbulence around 1,900 ft, and severe turbulence above 1,900 ft. Cloudy conditions were identified from about 750 ft through 3,650 ft. AIRPORT INFORMATIONAccording to FAA and maintenance records, the airplane was manufactured in 1977 and was powered by a Lycoming IO-360-A3B6D, 200-horsepower engine. The airplane’s most recent annual inspection was completed February 1, 2022, at 4,288.5 total aircraft hours. The altimeter static system and altitude reporting equipment were tested in accordance with CFR 91.411 on June 22, 2022.

The airplane was equipped with an IFR-certified Garmin 430 panel-mounted GPS, which allowed the pilot to select the desired airport, procedure, and then select from the approaches displayed in the drop-down menu. The correct sequence of menu selections provided all approach waypoints and precluded the need to manually enter an individual waypoint.

In interviews with local media after the accident, the pilot described the fog at the time of the accident as “pea soup,” and expressed concern about his altimeter working correctly.

Immediately after recovery of the accident airplane, a calibrated altimeter test instrument was installed by an airframe and powerplant mechanic with inspection authority under the supervision of an NTSB investigator. Functionality testing was performed at the as-found setting of 29.40 in the altimeter’s Kollsman window, then 29.92, and finally a Barometric Scale Error Test was performed through a range of 28.10 and 30.99. According to the test report, the altimeter was “well within the test allowable error at all ranges.” WRECKAGE AND IMPACT INFORMATIONLocal emergency services and utility personnel, along with an aircraft recovery specialist, separated the airframe from the engine and cut two of the three propeller blades to disentangle the engine from the tower structure; one blade was separated during impact. Examination of the airplane was conducted and supervised by an FAA aviation safety inspector, who confirmed continuity from the cockpit flight controls to all flight control surfaces. The propeller blades displayed similar twisting, bending, leading edge and tip gouging, and chordwise scratching.

Visual examination of the engine revealed only minor impact damage to intake and exhaust stacks, ignition P-leads, and a fuel pump drain port fitting. The engine rocker box covers were removed to facilitate the examination. The propeller was rotated by hand and continuity was established through the powertrain to the valvetrain and the accessory section. Compression was confirmed on all cylinders using the thumb method. The dual magneto ...